PAI is launching into space!
A couple months ago we posted on our Instagram
this #teasertuesday shot:
We are excited to finally announce a project we worked on; a dosimeter for astronauts on the International Space Station!
Wait a second, I thought PAI makes clocks, cables, and such? Well yes, we do, but we also work with other companies to develop their own products! One of these companies is our partner over at Mirion Dosimetry Services
division. They contacted our friend and frequent colleague Darius Mostowfi over at Sigma engineering to work alongside NASA to create a custom dosimeter for the International Space Station. Darius is a highly experienced electrical engineer and he needed some mechanical engineering to get this product space-worthy. It's good to have friends, thanks, Darius!
A dosimeter is a device that measures radiation. On top of being in zero gravity and in a vacuum, astronauts aren't afforded the luxury of having the same protections as we do here on earth. The earth's atmosphere and magnetic field shield us from a lot of the radiation emitted by the sun. When the astronauts are on the space station they have significantly less radiation protection as when they are outside of the earth's protection. NASA wanted to develop a dosimeter that would be small and worn on the clothes of the astronauts so that they can constantly monitor the radiation the astronauts were being subjected to.
The product had to be as small as possible while still being functional. One of the cooler features we designed into the product was the ability to replace the battery of the dosimeter quickly and easily while the astronauts are in space. We also had to make the dosimeters out of a space age material called Ultem. This material is very resistant to both heat and flame and if it does catch on fire it emits minimal smoke, something very important for a space station.
Because of the importance of the electronics in this project, Darius and our team had to design the dosimeter from the "inside out". This means we developed the layout of the circuit board and then wrapped around the mechanical exterior to create the smallest possible size. We went through multiple revisions with Darius and the NASA engineers to get the best possible layout and design.
While we were working out the approximate size and shape of the circuit board we made some sketches for NASA to review with some different overall design concepts.
After we got some feedback from astronauts and NASA engineers we narrowed down the design a little bit focusing on the large, easy to read screen NASA chose. These 3D printed blocks allowed the astronauts and engineers to feel the product's size.
Following some great feedback from the NASA team, we jumped into the mechanical design and figured out the toolless battery door as well as some internal features to hold Darius' electronics in place. In order to test these, we went back to our trusty 3D printer and created some more prototypes for NASA to get their hands on and test.
Then we finalized the design!
We also made a 3D model for NASA and made sure they were happy with everything. (Make sure you check out the VR orbit we made for this product, just click and drag around)
Once this was approved we started machining
We then test fit the parts to the electronics, thankfully everything fit juuuust right. Nice work everyone!
Then the machined parts when to a local painter who gave them a rich deep coat of purple. No, we didn't choose the color, bring it up with NASA.
Let's take a second to discuss the circuit boards that Darius designed. They are incredibly small, super thin, and have some incredibly complex circuitry in such a small space. The display chosen is a super thin, low power LCD made by Sharp that allows the product to have a screen which is always readable without hurting battery life. Check out the Sharp memory LCD technology
if you'd like to learn more. This board has a Bluetooth chip as well which allows the dosimeter to communicate with the computer systems on the space station. There are also 3 hidden switches which allow astronauts to control the functions of the product with the mechanical pencils they have onboard the space station. These boards also have the ability to detect radiation allowing them to be a great digital dosimeter.
*the board pictured above is missing the bluetooth module
From there the dosimeters are combined with the circuit boards to create the final product!
Check out the battery mechanism that allows the astronauts to replace the battery without tools and without the battery door floating away!
We are incredibly happy with how this project turned out and are honored to be able to say we worked on something that is going to launch into space and will help the brave men and women circling the earth above us. Thanks again to Darius at Sigma engineering for getting us this amazing job!
Our dosimeters are scheduled to head into orbit in June of 2018.
Next time, to the moon!
-The PAI team